Steam heating system



Jam 5, 1925c 1,522,474

' E: H. HQRSTKOTTE 5 TEAM HEATI NG S YS TEM Filed Dec. 12, 1923 Inventor; Edward fifiorsi'kofie His Attorney I Patented Jan. 6, 1925. I

umrso srarss PATENT ounce.

EDWARD E. HORSTKOTTE,' OF SGHZEN'ECTADY, NEW YORK, ASSIGNOR T GENERAL ELECTRIC CQMPANY, A. CORPORATION OF NEW YORK;

Ill

srnem HEATING sYs'rnm.

Application filed December 12, 1923. Serial No. 680,283.

To all whom it may concern."

Be it known that I, EDWARD H. HORST-- Ko'r'rE, a citizen of the United States, residing at Schenectady, inthe county of Sche nectady, State of New York, have invented certain new and useful Improvements in Steam Heating Systems, of which the following is a specification.

The present invention relates to steam heating systems wherein steam for heating purposes is generated by means of a generator or boiler of the electro type.

The object of my invention is to provide an improved system wherein the medium to be heated will be maintained automatically at a desired temperature and wherein the mechanism for accomplishing such result is of a simple character. v

An application of my invention and one to which it is well adapted is that of maintaining a tank of water or other liquid heat ed toadesired temperature and it is this application which I have illustrated and described in' my specification. It will be understood, however, that, this is only by way of example. It will be understood, also, that while I hereafter refer specifically to steam as the heating medium, I do so only as a matter of convenience and because water isalmost universally used in boilers at the present time, and that any other li uid found desirable may be used.

- or a consideration of what I believe to be novel and my invention, attention is di rected to the accompanying description and the claims appended thereto.

In the drawing, Fig. 1 is a diagrammatic view of a system embodying my invention, and Fig. 2 is a detail sectional view of a valve which ma be used therein.

Referring to t e drawing, 3 indicates the shell of an electric steam enerator or boiler and 4.- the electrodes whic project into the shell through suitable insulators 5. The electrodes may be connected to any suitable Source of current. In the present instance three electrodes are shown which adapts the generator or boiler for connection to a supply ofthree-phase alternating current. This arrangement of steam boiler or generator is shown only by way of example and is to be taken as typical of any suitable generator structure. In the present instance, the steam boiler is used to heat and main; tain at a constant temperature the liquid contained in a tank 6, this being, for ex-- am lo, a tank from which hot liquid is wit drawn from 1 time to time and cold liquid substituted. The liquid may be water, for instance.

According to my invention, 1 provide ad acent to the electric boiler, and at a v higher level, a storage reservoir '2 which has preferably a capacity-greater than that of shell 3 and I connect reservoir 7 to shell 3 by a conduit 8 through which it supplies Water to shell 3. In conduit 8 I then provide a valve 9 which is controlled by the temperature of the liquid in tank 6, and for heating the liquid in tank 6 I provide a heating coil 9' connected at one end by a pipe 10 to the steam space in the electric boiler and at the'other end by a pipe 11 to reservoir 7. This forms a closed heating circuit for the liquid in tank 6, steam from shell 3 being fed through pipe 10 to coil 9' where it gives up its heat to the liquid in tank 6, and is condensed and returned to reservoir 7 from whence it is again fed to the boiler through conduit 8. In an electric boiler of the type illustrated, the power input to the boiler and hence the amount of steam generated varies directly with "the depth to which the. electrodes are submerged, and valve 9 serves to vary this depth in accordance with the temperature of the liquid in tank 6. If the temperature of the liquid in tank 6 falls below the desired value, the arrangement is such that valve 9 opens to admit water from reservoir 7 to shell 3 thus further submerging electrodes 4 and eflecting the generation of steam more rapidly and in increase in pressure in the boiler. This causes a more rapid circulation of steam through coil 9 and increases the heating effectof the coil. Since reservoir 7 is at a level above shell 3, water flows from it to shell '3 by gravitywhen valve 9 is open. As the liquid in tank 6 is heated, valve 9 is gradually closed and when the desired temperature is reached is fully closed thus shutting off entirely the supply of water to the boiler. The level of the water in the boiler will then gradually drop as steam is generated thus raduall decreasin' the input to the boiler. %ventually it may all to a point below the bottom of the electrodes thus entirely cutting oil the flow of current through them. Shell 3 is preferably made of fairly small is considerable water in shell 3 and under these circumstances steam may be generated so rapidly in the boiler as to build up a pressure higher than desired for heating the liquid 'in-tank 6. That is to say, it would have atendency toheat the liquid too hot before the level in the boiler would be reduced to limit the power input sufliciently. To take care of this condition, I provide a by -pass pipe 12 which connects shell 3 to reservoir 7 and in which is located a springpressed relief valve 13 which opens toward reservoir7. This valve may be of any suitable type, it being normally held closed by spring 14 to prevent flow of water from reservoir 7 to shell 3 but opening against the action of spring 14 to permit water to flow from shell 3 to reservoir 7 when the pressure in shell 3 exceeds apredctermined value. With this arrangement, when the pressure in shell 3 exceeds the value for which spring past va substantially constant.

14 is set the liquid in shell 3 will be forced lve 13 to reservoir 7 thus quickly lowering the level in shell 3. By this means the temperature in tank 6 can be maintained Connected 'to ipe 8 is a pipe 8' in which is a valve 8". ipe 8 connects with a suitable water supply and serves to furnish make-up water to reser voir 7. On top of reservoir 7 is an air relief valve 7'.

Any suitable construction and arrangement may be usedfor controlling valve 9 in accordance with the temperature in tank 6. In the present instance, I have shown valve 9 as being provided with an operating arm 15 connected by astem 16 to a dia hra m 17 mounted in a casing 18. The un ersi e of diaphragm 17 is connected b a pipe 19 to a valve casing 20 in whic is a pilot valve 21 which moves between two seats 22 and 23 and is adapted to connect pipe 19 to either a flui'd ressuresupply pipe 24 or an atmospheric ischarge passage 25. (See Fig. 2). Pi e 24 may lead from any suitable source 0 pressure supply such as for example, a source of air pressure. Valve 21 is carried by a stem 26 which at its outer end engages the under-- side of a lever 27-fulcrumed at 28 on tank 6. Under the inner end of lever 27 is a spring 29 which 7 serves to bias the lever to a position in which it holds valve 21 on seat 22 against the action of the air pressure in p1pe 24 which tends to' open the valve. In tank 6 is a thermal device 30 connected by a conduit 31 to the underside of a diaphragm 32, the latter being connected by a link 33 to lever 27. The

thermal device is shown as being of a known type wherein a liquid contained in it expands and contracts with the temperature of the liquid in reservoir 6 and effects movements of diaphragm 32 through the liquid in conduit 31.

When the temperature of the liquid in tank 6 increases beyond a desired value, diaphragm 32 is operated to move lever 27 upward thus permitting the pressure in pipe 24 to open valve 21 and supply air pressure to the underside of diaphra 17. This results in moving diaphragm 1 upward and closing valve 9, and following this the level in shell 3 will lower as explained above, thus decreasing the input to the boiler and hence the amount of heat su plied through coil 9' to the liquid in tan 6. On the other hand, when the temperature of the liquid in tank 6 decreases below the desired value thenoperation takes place in a similar manner but in the opposite direction to effect an opening movement of valve 9 so as to increase the input to the electric boiler and hence the amount of heat supplied by coil 9 tothe liquid in tank 6. In actual o eration, when the heat demand of the liquid in tank 6 is fairly constant, the adjustment may be such, that valves 21 and 9 will each assume a balanced intermediate position and will move in one direction or the other as the demand for heat varies.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a vapor generator of the electrode type, of a reservoir for supplying liquid thereto, a heating coil connected to the vapor enerator, a medium which is heated by sai coil, and means controlled by the temperature of said medium for regu atin the flow of liquid from the reservoir -to t e vapor generator.

2. The combination with a vapor generator of the electrode type, of a reservoir for supplying liquid thereto, a heating coil, conduits connecting the heating coil to the vapor generator and to the reservoir, a

medium which is heated by said coil, and

means controlled by the temperature of said medium' for regulating the flow of liquid from the reservoir to the vapor generator.

3. The combination with a vapor generator of the electrode type, of a reservoir for supplying liquid thereto, a heating coil connected to the va or generator, a medium which is heated by said coil, means controlled by the temperature of said medium for regulating the flow of 'liquid from the reservoir to the vapor generator, and means actuated by the pressure'in the vapor generator for permitting liquid to flow from the generator back to the reservoir.

4. The combination with a tank containing a liquid'which it is desired to maintain at aconstant temperature, of a heatingcoil therein, a vapor generator of the electrode type, a reservoir containing a liquid supply for the generator, conduits connecting the heating coil to the generator and reservoir,

a conduit connecting the reservoir to the generator, a valve in the last named conduit, and means controlled by the temperature of the liquid'in the tank for operating said valve so as toregulate the level of the liquid in the vapor generator in accordance with the temperature of the liquid in said tank.

5. The combination with a tank containing a liquid which it is desired to maintain at a constant temperature, of a heating coil therein, a vapor generator of the electrode type, a reservoir containing a liquid supply for the generator, conduits connecting the heating coil to the generator and reservoir, a conduit connecting the reservoir to the generator, a valve in the last named conduit, means controlled by the temperature of the liquid in the tank for operating said valve so as to regulate the level of the liquid in the vapor generator in accordance with the temperature of the liquid in said tank, a second conduit connecting the, reservoir to the generator, and a valve therein con: trolled by the pressure in the vapor generator for permitting flow of liquid from the generator back to the, reservoir.

In witness whereof, I have hereunto set my hand this 11th day of December, 1923.

EDWARD H. HORSTKOTTE. 

